Super strong 2D titanium carbide MXene-based materials: a theoretical prediction

Abstract

Mechanical properties of two dimensional (2D) materials are essential for their applications since they determine their stiffness and stability [1][2][3]. The 2D materials with superior mechanical properties, e.g. graphene with the bulk Young's modules of about 1 TPa, can be promising candidates as composite materials, protective coatings, fibers and energy storage materials [4]. To this end, numerous studies have been devoted to discovering strong 2D materials. A recent study by Lipatov et al experimentally demonstrates that the 2D Ti 3 C 2 T x MXene monolayer is a novel strong 2D material, which possess the similar in-plane planar Young's modulus of graphene. This work paved the avenue to search other strong 2D MXene monolayer for the similar applications. MXenes is a new family of 2D transition metal carbides and carbonitrides with more than 70 known species, which can be synthesized by the exfoliation of MAX phases [5,6]. MXenes have a general formula of M n+1 X n , where M and X represent a metal and C/N, respectively. Whereas, n can be 1, 2, or 3 in the known MXene materials [5]. In practicality, MXenes are too chemically active, which can be synthesized through the surface functionalization using terminal groups including -OH, -O and -F. The terminal groups are termed as T. As such, the surface functionalized MXenes are labelled as M n+1 X n T x [7,8]. The surface functionalized MXenes have further led to numerous technological applications, e.g. energy storage [9, 10], electromagnetic interference shielding [11,12], composite materials [13], catalysts [14] and sensors [15]. While the structural and electronic properties of M n+1 X n T x have

Mechanical properties of lateral transition metal dichalcogenide heterostructures

“…With superb electronic and mechanical properties, two-dimensional (2D) ultrathin functional materials have shown great promise in a wide range of applications [1][2][3]. Over the past few years, layer-structured transition metal dichalcogenides (TMDs) such as Tungsten disulfide (WS2), Tungsten diselenide (WSe2), molybdenum disulfide (MoS2), and molybdenum diselenide (MoSe2) have attracted increasing attention due to their significant characteristics and physical properties including large exciton binding energy [4], band gap transition [5], and abundance of multiexcitons [6].…”

Multiscale numerical simulation of in-plane mechanical properties of two-dimensional monolayers

“…The in-plane elastic properties of some of the most studied 2D materials are presented in Table 5. 51,83,121,[147][148][149][153][154][155][156][157] Basically, in-plane mechanical properties (such as Young's modulus, shear modulus, hardness, and Poisson's ratio) can be calculated through the linear stress-strain or quadratic energystrain relationships. DFT methods are independent of any empirical parameters, which provide the highest accuracy and exibility, as evidenced by the data listed in Table 5.…”

“…They discovered that higher temperatures tend to signicantly decrease the fracture stress and strain almost linearly with temperature. The elastic modulus was, however, only affected at system temperatures higher than approximately 900 K. Thus, Exploring the behaviour of phosphorene and its oxides by investigating their mechanical properties Kazemi et al 121 MXene DFT-D3 In-plane planar Young's and shear moduli…”

“…Kazemi et al recently conducted a theoretical investigation to study the mechanical properties of 2D titanium carbide MXene-based materials utilizing DFT calculations. 121 They discovered that in-plane elastic constants, Young's and shear moduli increase over the thickness of the MXene systems. It further suggests that the improved mechanical properties of the functionalized MXenes.…”

First‐principles investigation of elastic and electronic properties of double transition metal carbide MXenes

“…62 Additionally, the calculated bond lengths illustrated in Figures 1 and S1, and Table S2 show an increase in the M′-C (M′ = Mo, Cr) bond lengths in the outermost layer after surface functionalization is consistent with other work. 48 The lowest change in bond lengths were observed for Mo 2 TiC 2 and Cr 2 TaC 2 substrates which implies the weakest effect of surface functionalization on the structural properties when compared to other structures. The shortest bond lengths of M′-C for V-based M 2 ′M′′C 2 correspond to their lower lattice parameters.…”